"Our operating model was that by improving cardiovascular risk, you also improve neurocognitive functioning," said James Blumenthal, lead author of the study, clinical psychologist at Duke University. "You improve brain health while improving the health of your heart."
"You can do something today to improve the brain of tomorrow," said Isaacson, who did not participate in the research.
The study was a first, said Blumenthal, who has long studied the effects of diet and exercise on depression and overall heart health.
"I do not think that another study has examined the separate and combined effects of exercise and diet on slowing cognitive decline in patients likely to develop dementia later in life." life, "he said.
The study was conducted among 160 adults with high blood pressure or other risk of cardiovascular disease, who never exercised physically. and who had checked cognitive problems such as difficulty making decisions, remembering or concentrating. The participants were on average 65 years old, two-thirds of whom were women, and equally divided between whites and minorities. Anyone diagnosed with dementia or unable to exercise was excluded.
A second group exercised but was not encouraged to dieting. During the first three months, this group was supervised in a cardiac rehabilitation center where they did non-tiring exercises three times a week: they warmed for 10 minutes, then 35 minutes of continuous walking or stationary cycling. During the last three months of the study, this group practiced at home by completing compliance registers monitored by research staff.
The third group did both: they exercised three times a week and followed the DASH diet. The fourth group only received advice to reduce his cardiovascular risk during a 30-minute conversation with a health educator, but he was told to not change his dieting habits and d & # 39; exercise.
Before starting their assigned path, participants underwent a battery of cognitive tests, a treadmill stress assessment and a food analysis. In addition, their blood pressure, blood sugar and lipids were recorded. The tests were repeated at the end of the study.
Change in only six months
The group that did only exercise found significantly greater improvements in its executive operating skills than the group that did not do any exercise.
"The results showed that controlled aerobic activity over a very short period of time can have a significant impact on the part of the brain that requires people to take care of themselves, pay their bills and the like," he said. Isaacson. "Not only can you improve, but you can improve in six months!"
Blumenthal noted: "Remember, it's older adults who are completely sedentary and who have a cognitive impairment checked out.We have had no abandonment, and everyone has been able to continue the exercise program and do it alone.This was great. "
The group that followed the DASH diet without physical exercise did not show any significant improvement in thinking skills, but Blumenthal and Iscaason pointed out that they had narrowly missed it.
"I would be cautious in saying that the diet did not help, because I believe that's probably the case," Isaacson said. "While the brain is sitting in a separate compartment, it's still part of the body, so anything that affects the body will also affect the brain."
However, it was the group that combined physical activity and the DASH diet that was most beneficial. This group scored an average of 47 points on overall executive thinking tests, compared to 42 points for those who did just exercise. and about 38 points for those who have been told not to change their eating and exercise habits.
In fact, the group that is dieting and exercising has reversed the aging of its nine-year-old brain.
Here's how it worked, said Blumenthal: At the start of the study, the group's average functional score was 93, or 28 years older than the average chronological age of 65.
But after only six months of exercise and the DASH diet, their executive function has improved by nine years, bringing their mental age back to 84 years.
The executive function of the control group was reduced by six months, or the length of the trial, which could be expected without any intervention, Blumenthal said.
No improvement in memory
Unfortunately, memory has not been improved for any of the groups. This is not surprising, said Isaacson.
"We can positively improve executive function with lifestyle interventions more quickly, but memory takes longer to respond," he said. "It could be that if this study had lasted 18 months or used a different type of brain regimen, memory would also have improved."
Isaacson added that it now needed further studies: "If we could bring together multiple centers to conduct multisite studies, we would learn more."
Because those who combined diet and exercise saw the most significant improvements, it may be that many lifestyle changes, not just diet and exercise, are needed to maximize success, said Blumenthal.
What's important, he said, is that "adopting a healthy lifestyle can increase your risk, your neurocognitive functioning, and it's not too late to start." Even in older people who have indications that their brain is compromised, they also benefit.